Archive for September, 2007

A new study just published in the New England Journal of Medicine, Early Thimerosal Exposure and Neuropsychological Outcomes at 7 to 10 Years, does not support a correlation between mercury in vaccines and neurological damage. It adds to the growing evidence that vaccines are safe and they do not cause neurological disorders. This study did not look at autism (a study that will be published next year looks, again, at vaccines and autism), but the mercury-causes-autism crowd are still unhappy with the results.

I have been following this issue closely for several years. Although my awareness of the issue goes back much farther, I started to seriously research the claim that the MMR vaccine, or that thimerosal in other vaccines, causes autism while researching an article on the topic for the New Haven Advocate. As a physician (a neurologist) and a skeptical activist I knew I had to get this issue right. I certainly did not want to falsely stoke the flames of public fear, nor did I want to cast myself in the role of denier.

Early on in my research I really did not know which way I was going to go with the issue. Should my bottom line be that there is real reason for concern here, that there is nothing to the claims, or that we really don’t know and will have to just wait for further research? But after reading through all the claims on both sides, and all the research, it was an easy call – vaccines, and specifically the MMR vaccine and thimerosal, do not cause autism, and the alleged autism “epidemic” is likely just an artifact. Those claiming there is a connection were drowning in conspiracy thinking, logical fallacies, and blatant pseudoscience. Meanwhile every piece of reliable clinical data was pointing in the same direction – no connection.

I have come to expect that when I post an entry on certain topics, such as creationism or alternative medicine, I am likely to get a comment that is suitable fodder for a follow up entry (although this can happen with any entry focussed on criticism of pseudoscience). These pseudosciences are highly developed, backed by a subculture of believers and an evolved and sophisticated (if completely misguided) doctrine. Since the ultimate conclusions promoted by believers in such pseudosciences are wrong, it is no surprise that the edifices of their claims and arguments are strewn with logical fallacies and misrepresentations of facts. Therefore I can always find something fallacious worthy of further discussion.

In response to my recent post on the latest unconvincing acupuncture study, John Wood, a self-described medical acupuncturist from London, wrote:

The fact that acupuncture has been used successfully in China for 2000 years with very few side effects is something that most surgeons, doctors and pharmacologists could only wish for.

This is a common claim of the pro-CAM crowd and is nothing but a giant logical fallacy – the argument from antiquity. This is a special case of the more general logical fallacy, the argument from authority. Such arguments follow the basic form of claiming that something is true, or that a particular claim has value, because the person or group promoting it has some virtue or positive attribute. In this case the implied claim is that the thing itself, acupuncture, works because it is blessed with the virtue of being ancient. This fallacy is further coupled with the implication that scientific medicine, surgery, and pharmacology suffer from the vice of modernity or youth.

Acupuncture is a complex “alternative” modality because something physical is actually happening – thin needles are being stuck through the skin and manipulated. So it is therefore not impossible that a physiological response is happening. It is much easier to comment on things like homeopathy and therapeutic touch where literally nothing physical is happening and the plausibility for any benefit is therefore zero. So if I try to answer the question in my title, much explanation and qualifications are required. To answer this question – does acupuncture work? – my current best answer based upon available evidence is a qualified no. This answer is not changed by the most recent study of acupuncture that is being touted by the press as evidence that acupuncture works. (Here is the original study, but a subscription is required.)

Let’s first look at this study, which was a German study of acupuncture for back pain. Dr. Heinz Endres studied 1,100 randomized patients with three treatment arms. The first received standard therapy – massage, anti-inflammatories, and heating pads. The second received acupuncture, and the third received sham acupuncture where the needles were inserted but not deeply, and not manipulated, and not in traditional acupuncture points. The study found 47% improvement in the acupuncture group, 44% in the sham acupuncture, and 27% in the standard therapy group after 6 months.

This single study, even taken just by itself, falls far short of demonstrating that acupuncture works. And of course we have to place it in the context of plausibility and the entire acupuncture literature. We also have to identify appropriate sub-questions.

The Discovery Institute – an Intelligent Design (ID) propaganda machine – has a blog called Evolution News and Views. Within its digital pages you will find an endless stream of mindless anti-evolution propaganda. Seriously, you could devote an entire blog just to correcting the nonsense spewing forth daily from this cesspool of antiscience. I try not to get sucked into it too often, but when my favorite ID blogger, Dr. Egnor, rears his head it’s hard to resist.

This week Dr. Egnor (a neurosurgeon who has decided to take up a sideline of embarrassing himself with scientific illiteracy and illogic) tries to make fun of an interesting paper in Nature Genetics. A press release about the paper summarizes the findings thusly:

“Humans have many more copies of (the salivary amylase gene) than any of their ape relatives, the study found, and they use the copies to flood their mouths with amylase, an enzyme that digests starch. The finding bolsters the idea that starch was a crucial addition to the diet of early humans, and that natural selection favored individuals who could make more starch-digesting protein.”

A new study sheds further light on the neurological phenomenon of the out-of-body (OOB) experience. This is an important area of research because, not only does it further our understanding of how the brain works, it is serving to demystify a common human experience (probably second only to waking dreams) that has contributed to a great deal of superstitious beliefs. It is also an important step in the victory of the neuro-materialists (those, like me, who feel that our mind in all of its aspects can be explained by brain function) against the dualists (those who claim that something other than the physical brain is needed to explain our mind and sense of self).

The paper, published in Science, is actually the collaboration of two teams: one from the University College London led by Dr. Henrik Ehrsson and the second from the Swiss Federal Institute of Technology in Lausanne. Both teams used a similar setup – they had subjects wear virtual reality goggles that contained an image of their own back produced by a camera setup behind them. Therefore they were looking at their own backs a few feet in front of them. Next they were given a sensory stimulation – they were touched on the back, and they could see their virtual selves being touched. In some subjects this triggered an OOB experience; they felt they were occupying the virtutal self that they saw and felt being touched. This experiment worked even if the “virtual self” they were viewing was actually a mannequin. Ehrsson’s team also showed that threatening the virtual image resulted in an autonomic response in the subjects, as if they were being threatened.

Dr. Mehmet Oz is the director of the Cardiovascular Institute at ColumbiaUniversityMedicalCenter – he’s a heart surgeon. He is also an influential advocate of so-called integrative medicine, and as such has been one of the wedges trying to get pseudoscience and superstition into modern medicine (unfortunately with some success). He was recently interviewed on the Speaking of Faith podcast.A reading of the transcript reveals the tortured logic, confused positions, and pseudoscience apologetics typical of the integrative medicine movement.

Early on in the interview Dr. Oz relates a story that I found very revealing of his ideology. He tells us that when he was a resident he had a patient with a bleeding ulcer who had lost quite a lot of blood. The patient was a Jehovah’s Witness and her family did not want her to receive any blood. Dr. Oz relates that her hematocrit (a measure of the red blood cells in the blood) was 4. I think he meant to say hemoglobin (a similar measure of red blood cell content) – a hematocrit (normally around 40) of 4 would be truly incompatible with life. A hemoglobin of 4 (normal hemaglobin is 12-15) is also extremely low and may be incompatible with life (I have never seen one so low) but is not as absurd as a hematocrit of 4 would be.

The Scientist.com is putting together a list of the top science blogs, so if you have not done so already please go there and vote for your favorites. Now, I’m not going to say I’m bitter because I have only had a single mention so far (thanks, Pekka). I understand my humble blog is still relatively new. It’s just that, it’s a little embarrassing when I’m standing around the water cooler with the other science bloggers and they are all bragging about their awards, mentions in prominent journals and websites, and all the votes they are getting from their readers (I mean Orac can be a real snob and Phil Plait will just not shut up about himself, and don’t even get me started on PZ Myers, the primadona).

Seriously, if you like what you read here please help me get on the radar of science blogs by giving me a kind mention.

In his now classic study Ioannidis systematically reviewed highly cited medical studies published in prominent journals, and then looked at the next 20 years of published studies to see if the initial results were later verified or refuted. What he found is that the majority were later refuted.

Several people sent me this article which tells the interesting tale of a Czech speedway racer who suddenly acquired the ability to speak “perfect” English, in an English accent, after hitting his head in a speedway accident. The report, missing many key details, is also likely grossly inaccurate.

The notion that a person can gain neurological function is nothing more than a movie cliche – one I suspected most people realized is not based in reality. But still the idea of someone regaining their lost memoris have being knocked in the head is a persistent one. There is enough fishy about such stories to make all but the most gullible scratch their heads and ask, “Does that really happen?” As a neurologist, I have often been asked that question.

This latest story is just a new version of this old and greatly implausible dramatic device. We are told by the Daily Mail (a news source that does not inspire me to much confidence) that 18 year old Matej Kus was knocked unconscious after a speedway accident. While he was being evaluated by the emergency medical technicians (EMT’s) his friends were shocked to hear him speaking fluent English. Matej is studying English, but at best speaks very broken minimal English. After a few hours this new ability vanished. Matej does not remember the incident – he has forgotten that day and the following two days.

Matej is quoted in the article as saying: “There must be plenty of the English language in my subconscious so hopefully I’ll be able to pick it up quickly next time.”